Abrasive compositions used for finishing processes, including polishing and lapping, generally have consisted of particles dispersed in a liquid. Diamonds have long been used as the abrasive particles in such compositions because of their hardness. Generally, the abrasive compositions have been in the form of slurries wherein the diamonds formed a discontinuous phase and, e.g., a hydrocarbon-based liquid, formed the continuous phase. For example, a common abrasive material such as that generally described above consists of diamonds, naptha, mineral oil, ethylene glycol, coolants or machine oil, and water.
The problem with the above-identified compositions is that the diamonds and/or abrasive particles tend to settle out of the liquid base and form cakes. This "caking" is often in the form of an agglomeration of particles which may scratch the pieces on which the abrasive material is later applied. Consequently, in order to avoid this problem, these abrasive materials must be constantly stirred and/or mixed when in use. In addition, another disadvantage of the above-identified compositions is the fact that these abrasive compositions generally utilize liquid bases containing hydrocarbons, which are by nature insoluble in water and may be hazardous materials and/or at least require special disposal procedures.
The present invention solves the above-identified problems by utilizing a water soluble liquid base as the continuous phase and the uniformly dispersed abrasive particles as the discontinuous phase. More importantly, the abrasive particles in the present invention do not fall out of suspension and thus, do not agglomerate. As a result, the present invention can be applied to equipment and/or other surfaces requiring polishing or lapping by spray, pump, or even gravity delivery systems with no mixing or stirring of any kind. Further, due to the durable suspension of the particles, consumers can purchase the product and store it for extended periods of time without having the abrasive particles cake at the bottom of the container and thus without the need to mix or stir the abrasive prior to use.
Moreover, since the present invention is water soluble, work pieces and any equipment used in finishing processes can be cleaned with soap and water and operators are subjected to fewer health hazards since the present invention, which has a MSDS rating of 1, contains no hydrocarbons or hazardous materials. Due to the fact that the present invention utilizes a water soluble liquid base and/or continuous phase, recovery of the abrasive particles after use of the abrasive composition is enhanced. The present invention also results in a more efficient abrasive composition which results in a savings of time and money.